'Als' Is not used in that way. 'Da / Während / Nun, da ' would be more acceptable, 'So' maybe. As a student -> Als student OK As I drove -> Als ich fuhr OK pas

'Als' Is not used in that way. 'Da / Während / Nun, da ' would be more acceptable, 'So' maybe. As a student -> Als student OK As I drove -> Als ich fuhr OK past tense As I start -> Da ich anfage, so ich anfage, während ich ... I think it's more practical for Germans to adopt the English usage then for you to learn this strange exception;)